Shuttle race cleaner



March 26, 1968 s. J. HAMLETT 3,374,757

SHUTTLE RACE CLEANER Filed Nov. 8, 1966 IN VE N TOR. avaday J /-Z4Md77' United States Patent M 3,374,757 SHUTTLE RACE CLEANER Sidney J. Hamlett, Parma, Ohio, assignor to White Consoiidated Industries, Inc., Cleveland, Ohio, a corporation of Delaware Filed Nov. 8, 1966, Ser. No. 592,860 7 Claims. (Cl. 112-192) This invention relates generally to sewing machines and more particularly to cleaning mechanisms for the shuttle race in sewing machine loop-taking mechanisms.

A usual construction for the loop-taking mechanism of sewing machines utilizes a shuttle which is oscillated through an arcuate path within a circular race to loop the bobbin thread around the needle thread to form the usual lockstitch formed by sewing machines. The shuttle is formed with an arcuate outer surface which slides against the mating race surface in a housing for the shuttle and is moved by means of an oscillating shuttle driver arranged to alternately engaged opposite ends of the shuttle to force it back and forth in its arcuate oscillating motion.

A particular problem encountered is maintaining the race clean and free from dirt of various types including lint and thread pieces which tend to increase the friction and decrease the available clearance for the shuttle and cause binding or sticking which adversely affects the performance of the sewing machine. Therefore, it has been recognized as desirable to provide some sort of cleaning arrangement to prevent the build-up of dirt and lint in the face and it has been recognized that because of the motion of the driver, the shuttle cleaning mechanism is best operated directly by the driver rather than by the shuttle itself.

Previous shuttle race cleaners have relied entirely on centrifugal force to provide the necessary rubbing force on the race. However, centrifugal force alone is not sufficient to apply proper force during low speed operation or regardless of speed at each point of reversal where the centrifugal force is low or non-existent. This latter problem is particularly important because it is at these points that the dirt accumulation is most severe, yet gravity tends to pull the cleaner out of contact with the race.

Therefore, it is a principal object of this invention to provide a novel and improved shuttle race cleaner for oscillating shuttle type sewing machine loop-taking mechanisms.

It is another object of this invention to provide a novel and improved shuttle race cleaner which will provide positive cleaning of all portions of the shuttle race.

It is still another object of this invention to provide a novel and improved shuttle race cleaner having an improved arrangement for tensioning the cleaner against the race to provide proper control of the rubbing forces between the cleaner and the race.

Further objects and advantages of this invention will readily become apparent from the disclosure of the preferred embodiment of this invention in which, briefly described, the driver is formed with an axial slot on the inner surface underlying the driver spring and the cleaner has a pair of arcuate rubbing members conformable to the race and connected to the center-support section. This support section has a pair of tabs, one of which fits in the driver slot and the other adjacent the outer surface of the driver to positively hold the support section in position. A leaf spring is secured at its center to the support section so that its free ends press against the outer surface of the driver and thus press the support section and the cleaner as a unit radially outward against the race so as to provide a uniform and balanced tension without being dependent upon the centrifugal force applied to the cleaner during operations so as to insure 3,374,757 Patented Mar. 26, 1968 positive cleaning action during low speed operation of the machine and at the ends of the race during reversal of the driving motion.

Further features and advantages of this invention will readily become apparent to those skilled in the art upon more complete comprehension of the preferred embodiment as shown in the drawings and in the following detailed description.

In the drawings:

FIGURE 1 is an end-elevational view of an oscillating shuttle driver mechanism of a sewing machine with the shuttle and cover plate removed;

FIGURE 2 is an enlarged cross-sectional View taken on line 22 of FIGURE 1; and

FIGURE 3 is an enlarged exploded perspective view with parts broken away showing details of the cleaner and the structure for mounting it on the shuttle driver.

Referring now to the drawings in geater detail, a looptaking mechanism of a sewing machine generally includes a housing having a support portion 11 for mounting the housing on the sewing machine together with a generally arcuate race portion 13 which terminates at pointed upper ends 14 and 15 spaced apart to allow entry of the needle into the race space so that the needle thread may be picked up by the shuttle.

The housing 10 provides a circular shuttle race formed in a race portion 13- with an axially extending cylindical surface 17 and an inner radial end face or radial surface 18 to confine the shuttle therein while providing a smooth bearing surface. To retain the shuttle within the race, it is closed at its outer end by a cover 24) held in place by spring loaded latches .19. The cover 20 fits within an enlarged opening 21 in the outer end of the housing 10 and against an inner end face 22 which positions the inner side 24 of the cover 2% so as to provide the outer side of the U-shaped channel which serves to guide the shuttle.

The driving mechanism for the shuttle includes an oscillating shaft 26 driven by the sewing machine mechanism and arranged to oscillate through the necessary angular movement to operate the shuttle. On the end of the shaft 26 is secured a shuttle driver hub 27 from which extends an arm 28 which terminates in the axially extending driver center section 2%. Left and right arms and 31, respectively, extend arcuately from the center section 29 a spaced distance inward from the race 17. A shuttle driver spring 33 is secured to the inner surface of the center section on the arms by means of screws 3 which engage the arms 30 and 31. It will be understood that the spring 33 extends over the ends of the arms 30 and 31 to cushion the driving force for the shuttle which alternately engages the opposite ends of the driver arms. It is understood that this construction of the raceway and shuttle driving mechanism disclosed herein is by way of example and may be considered typical of constructions used by a large number of sewing machines and has been shown by way of example and not by limitation of a structure for use with the shuttle race cleaner of this invention.

The shuttle race cleaner is mounted on the center section 29 of the shuttle driver between the driver and the race to make rubbing contact with the race. The cleaner includes a clip 36 preferably formed from a strip of metal of substantially uniform width to engage the inner and outer sides of the driver center section to hold the cleaner in place. The clip 36 has a channel-shaped center section 37 on the outer side of the driver center section from which extends a lower tab or lip 38 which is engageable with the outer surface of the center section to limit radially inward movement of the clip. The clip 36 includes an end portion 39 extending from the opposite side of the center section 37 to curve around radially inward to the inner side of the driver where it extends axially to form a tab or lip 41. The tab 41 extends axially within a groove 35 formed on the inner surface of the driver center section 29 beneath the spring 33. The groove 35 is made to have a width to position the tab 41 against sidewise movement and has a radial depth greater than the thickness of the tab 41 so as to allow the cleaner to "be self-positioning and allow radially outward movement as required to maintain proper contact with the race. As Seen, the lower tab 33 and top tab 41 .securely position the clip 36 on the driver while the end portion 39 extends axially outward so that it may easily be grasped by the fingers for removal by simple outward sliding movement once the raceway cover has been removed.

To provide the proper tensioning of the cleaner, a spring 43 is provided with the center section 44 beneath the clip-center section 37 and has a pair of spring arms 45'and 46 which at their outer ends contact the driver 'arms 30 and 31, respectively. Thus, the spring 43 pro- 'vides a positive outward biasing force at the center section 44. Outward of the spring center section 44 is a cleaner center section 43 and this center section together with the spring center section 44 and the clip center section 37 are firmly secured together by means of a screw 49 which is threadedly engaged in the clip center section 37. l The cleaner has left and right arms 51 and. 52 having outer peripheries with substantially the same radius as that of the raceway surface 17 so as to make abutting contact therewith. These sections 51 'and 52 terminate at tips 53 and 54 which are arranged to be positioned that when the driver reaches the ends of its motion, they will extend beyond the race portion ends 14 and 15 as indicated in dotted lines at 58 and 59 so as to insure that all portions of the race will be engaged by the shuttle race cleaner arms '51 and 52 under rubbing pressure du'ring a complete cycle of the driver. This is particularly important at the upper ends of the race where dirt tends to accumulate most rapidly and where the position of the cleaner and the minimal centrifugal force during the reversal of motion tends to cause the cleaner to fall downward out of contact with the race. In order to provide accommodations for any lint that may be picked up, the outer surfaces of the arms 51 and 52 may be provided with grooves 56 within which the material may collect.

Because the spring arms 45 and 46 engage the driver arms 30 and 31 at axially spaced points, and because the spring center section is firmly clamped to the clip-center section 37 and the cleaner center section 48, the unit is quite rigid and the application of this biasing force at spaced points gives stability and insures a balanced contact force on both the cleaner arms 51 and 52. The cleaner arms 51 and 52 are preferably formed of plastic within which is embedded the center section 48 for purposes of insuring rigidity and to insure maximum strength at the center point. Because the top tab 41 is firmly located within the groove 35, a positive driving force is applied directly to the metal clip member by the sides of groove 35. Since the tab 41 is firmly positioned and held in place both by the sides of the groove 35 and by the overlying spring 33, the cleaner cannot fall out of place when the machine is stopped regardless of the position of the driver 'yet there is no restriction against the axial movement necessary for easy removal of the cleaner.

path, a shuttle driver mounted in said housing for oscillating movement about an axis concentric with said race and spaced radially inward from said race, an axial groove on the inner surface'of said shutter driver, a shuttle race cleaner supported in said race and having an arcuate surface generally conforming with said race, a clip having parallel tabs secured to said shuttle race cleaner, one of said tabs engaged in said groove and the other tab engaging the outer surface of said shuttle driver whereby said shuttle race cleaner is oscillated with said shuttle driver by the driving connection of said clip in said groove and spring means operable to bias said shuttle race cleaner into engagement with said race.

2. A sewing machine loop-taking mechanism as set forth in claim 1 wherein said spring means is a spring carried by said shuttle race cleaner and engageable with said shuttle driver.

3. A sewing machine loop-taking mechanism as set forth in claim 2 wherein said spring is a leaf spring secured near its center to said shuttle race cleaner and having two projecting ends extending into engagement with the outer surface of said shuttle driver.

4. A sewing machine loop-taking mechanism compris ing a housing defining a circular race, a shuttle slidably guided in said race for oscillating movement in an arcuate path, an oscillating driving shaft extending into said housing, a shuttle driver drivab-ly secured to said shaft for oscillating movement Within said housing, said shuttle driver having a central portion secured to said shaft and a flattened arcuate driving portion extending generally parallel to said shaft and extending circumferentially in either direction from said center section, an axial groove formed in the inner surface at the center of said driving portion of said shuttle driver, a shuttle race cleaner positioned between said shuttle driver and said race and hav ing an arcuate outer surface gene-rally conforming with said race, said shuttle race cleaner having a center section, a clip member secured to said center section, said clip having a first tab secured in said groove and a second tab engageable with the outer surface of said driver to limit radially inward movement of said shuttle race cleaner, and a leaf spring secured to said shuttle race cleaner between said shuttle race cleaner and said clip, said leaf spring having ends extending circumferentially in both directions from said clip and radially inward to engage the outer surface of said shuttle driver to bias said shuttle race cleaner against said race.

5. A sewing machine loop-taking mechanism as set forth in claim 4 including a shuttle driving spring secured to the inner surface of said shuttle driving portion and overlying said groove, said groove having a radial depth greater than the radial thickness of said first tab.

6. A sewing machine loop-taking mechanism as set forth in claim 4 including screw means'securing together said shuttle race cleaner, said leaf spring and said clip as a unit.

7. A sewing machine loop-taking mechanism as'set forth in claim 6 wherein said clip includes a portion carrying said first tab and projecting axially beyond said shuttle race cleaner and said shuttle driver for gripping purposes to allow easy removal of said unit from said shuttle driver. 7

References Cited UNITED STATES PATENTS 2,822,773 2/1958 7 Ivanko 1l2l92 X 2,842,081 7/ 1958 Kurihara 112--192 3,176,642 4/1965 LOVG 112-232 FOREIGN PATENTS 859,637 1/1961 Great Britain. 423,458 7/1947 Italy. 7

HERBERT F. ROSS, Primary Examiner. 

1. A SEWING MACHINE LOOP-TAKING MECHANISM COMPRISING A HOUSING DEFINING A CIRCULAR RACE, A SHUTTLE SLIDABLY GUIDED IN SAID RACE FOR OSCILLATING MOVEMENT IN AN ARCUATE PATH, A SHUTTLE DRIVER MOUNTED IN SAID HOUSING FOR OSCILLATING MOVEMENT ABOUT AN AXIS CONCENTRIC WITH SAID RACE AND SPACED RADIALLY INWARD FROM SAID RACE, AN AXIAL GROOVE ON THE INNER SURFACE OF SAID SHUTTER DRIVER, A SHUTTLE RACE CLEANER SUPPORTED IN SAID RACE AND HAVING AN ARCUATE SURFACE GENERALLY CONFORMING WITH SAID RACE, A CLIP HAVING PARALLEL TABS SECURED TO SAID SHUTTLE RACE CLEANER, ONE OF SAID TABS ENGAGED IN SAID GROOVE AND THR OTHER TAB ENGAGING THE OUTER SURFACE OF SAID SHUTTLE DRIVER WHEREBY SAID SHUTTLE RACE CLEANER IS OSCILLATED WITH SAID SHUTTLE DRIVER BY THE DRIVING CONNECTION OF SAID CLIP IN SAID GROOVE AND SPRING MEANS OPERABLE TO BIAS SAID SHUTTLE RACE CLEANER INTO ENGAGEMENT WITH SAID RACE. 